H.02.70 High

Baxi H.02.70 Fault Code

Also written as H0270 — same fault.

The Baxi H.02.70 fault code means: your boiler is having trouble communicating with an external heat recovery system or sensor, causing it to pause operation until it can confirm everything is running correctly.. It appears on 5 Baxi models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: External unit heat recovery test failed
Typical repair cost £150-300 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Baxi models that show the H.02.70 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Baxi H.02.70 fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026